Lead-in-device passing a conductor through the cover of an electrical precipitation apparatus

ABSTRACT

Lead-in-device receiving a conductor which passes through the cover of an electrical precipitation apparatus and down to its electrode system, the electrical precipitation apparatus being used in the production of phosphorus. A middle portion of the conductor is concentrically surrounded by a duct and a sealing cup is disposed above the cover of the electrical precipitation apparatus concentrically with respect to the conductor. Above the sealing cup, the conductor is encircled by an insulator which is radially spaced therefrom and above the insulator, the conductor is concentrically surrounded by a bellows, of which the upper end is fast with the conductor. An annular chamber is disposed between the insulator and the bellows, the lower surface of the said annular chamber being apertured to provide passages, whereby a gaseous medium can be continuously supplied to the annular space between the said insulator and the said conductor. Elastic packing rings provide seals between the insulator and the annular chamber situated above it, and between the insulator and the sealing cup situated below it, and spring pressed elements urge the annular chamber into contact with the insulator, the springpressed elements having mountings which bear against crossmembers fast with the conductor.

United States Patent [191 Ebert et al.

[ Nov. 20, 1973 I LEAD-IN-DEVICE PASSING A CONDUCTOR THROUGH THE COVEROF AN ELECTRICAL PRECIPITATION APPARATUS [75] Inventors: Hans Ebert,Hurth-Efferen;

Friedrich Wilhelm Kampmann; Ursus Thummler, both of Erftstadt Liblar;Hugo Werner, l-Iurth-Hermulheim, all of Germany [73] Assignee: KnapsackAktiengesellschaft,

Knapsack near Cologne, Germany 22 Filed: Feb. 26, 1973 21 Appl. No.:335,598

[30] Foreign Application Priority Data Mar. 2, 1972 Germany P 22 09999.6

[52] US. Cl 174/3l.5, 55/120, 55/146, 174/12 BH [51] Int. Cl B03c 3/34,l-lOlb 17/26 [58] Field of Search 174/12 BH, 14 BH,

174/15 BH, l6 BH, 18, 31 R, 31.5; 55/120, 140,146,148

[56] References Cited UNITED STATES PATENTS 3,595,983 7/1971 Muller eta1. 174/31.5 3,627,898 12/1971 lbach et a1. 174/31.5 X

Primary Examiner-Laramie E. Askin Attorney-Arthur G. Connolly et al.

[57] ABSTRACT Lead-in-device receiving a conductor which passes throughthe cover of an electrical precipitation apparatus and down to itselectrode system, the electrical precipitation apparatus being used inthe production of phosphorus. A middle portion of the conductor isconcentrically surrounded by a duct and a sealing cup is disposed abovethe cover of the electrical precipitation apparatus concentrically withrespect to the conductor. Above the sealing cup, the conductor isencircled by an insulator which is radially spaced therefrom and abovethe insulator, the conductor is concentrically surrounded by a bellows,of which the upper end is fast with the conductor. An annular chamber isdisposed between the insulator and the bellows, the lower surface of thesaid annular chamber being apertured to provide passages, whereby agaseous medium can be continuously supplied to the annular space betweenthe said insulator and the said conductor. Elastic packing rings provideseals between the insulator and the annular chamber situated above it,and between the insulator and the sealing cup situated below it, andspring pressed elements urge the annular chamber into contact with theinsulator, the spring-pressed elements having mountings which bearagainst crossmembers fast with the conductor.

9 Claims, 1 Drawing Figure United States Patent 1 [111 3,773,966

Eb'ert et al. Nov. 20, 1973 LEAD-lN-DEVICE PASSING A CONDUCTOR THROUGHTHE COVER OF AN ELECTRICAL PRECIPITATION APPARATUS The present inventionprovides a lead-in device receiving a conductor which passes through thecover of an electrical precipitation apparatus and down to its electrodesystem, the precipitation apparatus being used in the production ofphosphorus, wherein a middle portion of the conductor is concentricallysurrounded by a duct; wherein a sealing cup is disposed above the coverof the electrical precipitation apparatus concentrically with respect tothe conductor; wherein, above the sealing cup, the conductor isencircled by an insulator which is radially spaced therefrom; andwherein, above the insulator, the conductor is concentrically surroundedby a bellows, of which the upper end is fast with the conductor.

A lead-in device receiving a conductor which passes through the cover ofan electrical precipitation apparatus has already been described,wherein the conductor, housed in a duct arranged concentricallytherewith, is surrounded by an insulator, which is positioned above thecorner of the electrical precipitation apparatus and is radially spacedfrom the conductor, and wherein an insulating bush is mounted on theconductor, the insulating bush being surrounded by a barrier disc so asto leave a narrow gap therebetween. In this device, the insulator, theinsulating bush and the barrier disc are conveniently ofpolytetrafluoroethylene. Positioned above the insulator is a bellows, ofwhich the lower and upper ends are fast with the insulator andconductor, respectively. The space between the bellows, the insulator,the barrier disc and the insulating bush is occupied by a sealing gasmaintained under overpressure. Arranged concentrically around theconductor and positioned between the duct and the cover of theelectrical precipitation apparatus is a sealing cup, of which the lowerportion conveniently has water therein and of which the upper portionprovides a pipe connection running to a chimney.

A difficulty encountered during the operation of the above lead-indevice is that the surfaces of the insulator, the insulating bush andthe barrier disc, which as just mentioned are conveniently ofpolytetrafluoroethylene, are rapidly contaminated, and thereby renderedelectrically conductive, by dust particles which are ejected from theelectrical precipitation apparatus as a result of pressure variationstherein; this difficulty is encountered despite the use of nitrogen, forexample, as an incombustible sealing gas. This superficial contaminationhas even been found to lead in many cases to the destruction of theserelatively costly insulating elements, due to continual electricflash-overs.

It is accordingly an object of the present invention to provide alead-in device receiving a conductor which passes through the cover ofan electrical precipitation apparatus, which device is free from thedisadvantages referred to above and makes it possible for the highvoltage applied to the conductor to produce corona currents in theelectrical precipitation apparatus, avoiding wasteful currents leakingover the surfaces of the insulating elements.

According to the present invention, we provide a lead-in devicereceiving a conductor which passes through the cover of an electricalprecipitation apparatus and down to its electrode system, the electricalprecipitation apparatus being used in the production of phosphorus;wherein a middle portion of the conductor is concentrically surroundedby a duct and a sealing cup is disposed above the cover of theelectrical precipitation apparatus concentrically with respect to theconductor; wherein, above the sealing cup, the conductor is encircled byan insulator which is radially spaced therefrom; and wherein, above theinsulator, the conductor is concentrically surrounded by a bellows, ofwhich the upper end is fast with the conductor; the lead-in devicecomprising: an annular chamber disposed between the insulator and thebellows, the lower surface of the said annular chamber being aperturedto provide passages whereby steam or another gas vapour can becontinuously supplied to the annular space between the said insulatorand the said conductor; elastic packing rings which provide sealsbetween the insulator and the annular chamber situated above it, andbetween the insulator and the sealing cup situated below it; andspring-pressed elements urging the annular chamber into contact with theinsulator, the springpressed elements having mountings which bearagainst cross-members which are fast with the conductor.

Preferred features of the lead-in device of the present invention, whichcan be used singly or in combination, provide:

a. for the insulator to be of quartz, or

b for the insulator to be of quartz glass, or

c for the insulator to be of polytetrafluoroethylene;

d for the insulator to have a length equal to its internal diameter, or

e for the insulator to have a length larger than its internal diameter;

ffor the annular chamber to have a pipe connection connecting theannular chamber to supply means for steam or another gas or vapour,through an insulating joint; and

g for the insulating joint to have a length equal to the internaldiameter of the insulator, or

h for the insulating joint to have a length larger than the internaldiameter of the insulator.

In the lead-in device of the present invention, the insulatorcan be aplain cylinder of quartz, quartz glass or polytetrafluoroethylene, withno attachments. As a result, it is possible for the purchase, assemblyand maintenance costs to be reduced substantially by 50 percent,compared with the costs of known lead-in de vices. To avoid thedeposition of, for example, condensed phosphorus and/or impuritiescontaining phosphorus and carbon, on the surface of the insulator, useshould preferably be made of a system whereby steam ,at to C is causedto flow into the interior of the insulator. If contaminating materialshould ever de posit on the insulator, for example, as a result of abreakdown in the steam supply system, it is possible for the inside ofthe insulator to be rapidly rinsed, the power to the electricalprecipitation apparatus being switched off, using as a rinsing means thecondensed water which is at first produced once the supply of steam isresumed. Following this, the rising steam temperatures effect drying ofthe insulator, and restore its full insulating properties.

In addition to this, the steam flowing through the insulator and theduct into the electrical precipitation apparatus has been foundfavorably to influence the separation of dust, in the electricalprecipitation apparatus.

An embodiment of the device of the present invention is showndiagrammatically (generally in axial section) in the single FIGURE ofthe accompanying drawmg.

As can be seen from the FIGURE, a conductor 1 is arranged to projectthrough a cover 2 down to the electrical system of an electricalprecipitation apparatus 3. The conductor 1 is surrounded by a duct 4projecting, from a level above the cover 2, into the interior of theelectrical precipitation apparatus 3. Above the duct 4, the conductor 1is surrounded by a cylindrical insulator 5, which is radially spacedtherefrom and of which the lower end is sealed by an elastic packing 6which is supported by an upper flange provided on a bell-shaped member14 forming an inner part of a sealing cup 12. At the upper end of theinsulator 5, which is also sealed by an elastic packing 6, is an annularchamber 9 of which the lower surface is apertured to provide outlets 11.The annular chamber 9 is urged towards the insulator by spring-pressedrods 7 mounted in sleeves which bear against cross-members 19 fast withthe conductor 1. The annular chamber 9 is further provided with a pipeconnection 10 opening laterally thereinto. The pipe connection 10 and aninsulating joint 8 connect the chamber 9 to a conduit 21 supplyingsteam, for example. Disposed above the annular chamber 9 is a bellowswhich is secured at its lower end to a flange provided on the chamber 9and is secured at its upper end to the conductor 1. 4

The bell-shaped member 14 is arranged so as to open out into the sealingcup 12, its upper end passing through the cover 13 of the sealing cup12. The lower portion of the sealing cup 12 contains a sealing liquid15, for example water, which is supplied thereto through an inlet 17 andremoved therefrom through an outlet 16. The upper portion of the sealingcup 12 has an off-gas connection 18 running to a chimney.

The claims:

1. Lead-in device receiving a conductor which passes through the coverof an electrical precipitation apparatus and down to its electrodesystem, the electrical precipitation apparatus being used in theproduction of phosphorus; wherein a middle portion of the conductor isconcentrically surrounded by a duct and a sealing cup is disposed abovethe cover of the electrical precipitation apparatus concentrically withrespect to the conductor; wherein, above the sealing cup, the conductoris encircled by an insulator which is radially spaced therefrom; andwherein, above the insulator, the conductor is concentrically surroundedby a bellows, of which the upper end is fast with the conductor; thelead-in device comprising: an annular chamber disposed between theinsulator and the bellows, the lower surface of the said annular chamberbeing apertured to provide passages whereby steam or another gas orvapour can be continuously supplied to the annular space between thesaid insulator and the said conductor; elastic packing rings whichprovide seals between the insulator and the annular chamber situatedabove it, and between the insulator and the sealing cup situated belowit; and spring-pressed elements urging the annular chamber into contactwith the insulator, the springpressed elements having mountings whichbear against cross-members which are fast with the conductor.

2. Lead-in device as claimed in claim 1, wherein the insulator is ofquartz.

3. Lead-in device as claimed in claim 1, wherein the insulator is ofquartz glass.

4. Lead-in device as claimed inclaim 1, wherein the insulator is ofpolytetrafluoroethylene.

5. Lead-in-device as claimed in claim 1, wherein the insulator has alength equal to its internal diameter.

6. Lead-in-device as claimed in claim 1, wherein the insulator has alength larger than its internal diameter.

7. Lead-in-device as claimed in claim 1, wherein the annular chamber hasa pipe connection connecting the annular chamber to supply means forsteam or another gas or vapour, through an insulating joint.

8. Lead-in-device as claimed in claim 7, wherein the insulating jointhas a length equal to the internal diam eter of the insulator.

9. Lead-in-device as claimed in claim 7, wherein the insulating jointhas a length larger than the internal diameter of the insulator.

l i l

1. Lead-in device receiving a conductor which passes through the coverof an electrical precipitation apparatus and down to its electrodesystem, the electrical precipitation apparatus being used in theproduction of phosphorus; wherein a middle portion of the conductor isconcentrically surrounded by a duct and a sealing cup is disposed abovethe cover of the electrical precipitation apparatus concentrically withrespect to the conductor; wherein, above the sealing cup, the conductoris encircled by an insulator which is radially spaced therefrom; andwherein, above the insulator, the conductor is concentrically surroundedby a bellows, of which the upper end is fast with the conductor; thelead-in device comprising: an annular chamber disposed between theinsulator and the bellows, the lower surface of the said annular chamberbeing apertured to provide passages whereby steam or another gas orvapour can be continuously supplied to the annular space between thesaid insulator and the said conductor; elastic packing rings whichprovide seals between the insulator and the annular chamber situatedabove it, and between the insulator and the sealing cup situated belowit; and spring-pressed elements urging the annular chamber into contactwith the insulator, the spring-pressed elements having mountings whichbear againsT cross-members which are fast with the conductor.
 2. Lead-indevice as claimed in claim 1, wherein the insulator is of quartz. 3.Lead-in device as claimed in claim 1, wherein the insulator is of quartzglass.
 4. Lead-in device as claimed in claim 1, wherein the insulator isof polytetrafluoroethylene.
 5. Lead-in-device as claimed in claim 1,wherein the insulator has a length equal to its internal diameter. 6.Lead-in-device as claimed in claim 1, wherein the insulator has a lengthlarger than its internal diameter.
 7. Lead-in-device as claimed in claim1, wherein the annular chamber has a pipe connection connecting theannular chamber to supply means for steam or another gas or vapour,through an insulating joint.
 8. Lead-in-device as claimed in claim 7,wherein the insulating joint has a length equal to the internal diameterof the insulator.
 9. Lead-in-device as claimed in claim 7, wherein theinsulating joint has a length larger than the internal diameter of theinsulator.